Conventionally, a reactor is built in as a part of an electric conversion circuit mounted on an electrically driven vehicle such as a hybrid vehicle. Such a reactor is used in a converter or the like which boosts DC electric power supplied from a battery and outputs the boosted DC electric power to a motor which is a power source.
A reactor generally includes two or more core members made from a magnetic material; a reactor core which is formed by joining the core members in an annular shape with a non-magnetic gap plate sandwiched therebetween; and a coil positioned around a coil mounting position of the reactor core including the gap plate. The reactor including the reactor core and the coil is mounted on a vehicle in a state that the reactor is fixed within a case made from a metal such as aluminum alloy, by means of a bolt or the like.
As a conventional art document related to such a reactor, for example, JP 2009-99793 A (Patent Document 1) discloses a manufacturing method of a reactor which includes enclosing and fixing a reactor core with a coil in a housing; and fixing the reactor in the housing by filling and hardening a silicon resin among the housing, the reactor core, and the coil.
Further, JP 2009-27000 A (Patent Document 2) discloses a reactor device in which a core unit is formed with two or more I-shaped magnetic cores which are joined with a gap therebetween; a reactor core is formed in a generally annular shape by joining magnetic U-shaped cores between ends of two of the core units; a coil is formed around periphery of the core unit to form a reactor; and a resin mold body is formed between the reactor and the housing with the reactor enclosed within the housing. It is described that in this reactor device, the resin mold body is formed where the coils of the reactor are formed; whereas the resin mold body is not formed between the U-shaped cores and the housing.